Merck & Co has signed an immunotherapy pact with Advaxis for prostate cancer involving its high-profile PD-1 checkpoint inhibitor pembrolizumab.

The collaboration will evaluate Advaxis' Lm (Listeria monocytogenes)-LLO cancer immunotherapy ADXS-PSA as monotherapy and in combination with pembrolizumab in a Phase I/II study of patients with previously treated metastatic, castration-resistant prostate cancer. No financial details have been disclosed and Advaxis will fund the study, while both companies will collaboratively oversee the conduct of the study, which is planned to begin in early 2015.

Advaxis said preclinical evidence suggests that its Lm-LLO immunotherapies in combination with a PD-1 inhibitor may lead to an enhanced anti-tumour immune response. Chief executive Daniel O'Connor added that the combo holds significant promise for the treatment of prostate and other cancers."

Eric Rubin, head of oncology at Merck Research Laboratories, said collaborations such as this are an integral part of the company’s strategy “to evaluate the potential of pembrolizumab in multiple combinations”. Pembrolizumab, which has been filed on both sides of the Atlantic, is currently being evaluated across more than 30 types of cancers, as monotherapy and in combination and by the end of 2014, its development programme will top 24 clinical trials, involving some 6,000 patients.  

As for Advaxis, it sealed a deal with AstraZeneca to evaluate another cancer vaccine, ADXS-HPV, with the latter’s own PD-1 checkpoint inhibitor MEDI4736 in a Phase I/II study  in patients with human papillomavirus-associated cervical and head and neck cancers.